Lithium oxide (O), or lithia, is an inorganic chemical compound. It is a white or pale yellow solid. Although not specifically important, many materials are assessed on the basis of their Li<sub>2</sub>O content. For example, the Li<sub>2</sub>O content of the principal lithium mineral spodumene (LiAlSi<sub>2</sub>O<sub>6</sub>) is 8.03%.
Lithium oxide forms along with small amounts of lithium peroxide when lithium metal is burned in the air and combines with oxygen at temperatures above 100 ðC:
Pure can be produced by the thermal decomposition of lithium peroxide, , at 450 ðC
Solid lithium oxide adopts an antifluorite structure with four-coordinated Li+ centers and eight-coordinated oxides.
The ground state gas phase molecule is linear with a bond length consistent with strong ionic bonding. VSEPR theory would predict a bent shape similar to .
Lithium oxide is used as a flux in ceramic glazes; and creates blues with copper and pinks with cobalt. Lithium oxide reacts with water and steam, forming lithium hydroxide and should be isolated from them.
Lithium oxide absorbs carbon dioxide forming lithium carbonate:
The oxide reacts slowly with water, forming lithium hydroxide: